World-first ultrasound biosensor promises real-time tumor tracking
Ultrasound has become an indispensable tool for showing us internal structures of the human body, but could it come to offer a far more detailed and dynamic picture as the body responds to drugs or disease? Scientists in Australia have leveraged the technology to develop what they call the world’s first ultrasound biosensor, which they say could be used to inexpensively monitor tumors or reveal the impacts of stroke.
Tiny, non-toxic biosensors that can be implanted in the body could offer physicians and researchers an entirely new perspective on different bodily processes. These could be battery-powered devices that live under the skin to track breathing and heart rates by detecting subtle movements, or others that reveal how the body is responding to implanted prosthetics by monitoring the surrounding tissues.
The scientists behind the new research at Australia’s Monash University set out to develop a biosensor that could monitor drug levels and biological molecules inside the body through ultrasound. Today’s ultrasound imaging relies on contrasting agents that consist of gas-filled microbubbles, though these only work for up to around 20 minutes, so the team set its sights on a solution with greater staying power.
This led them to develop nanoparticles consisting of a silica core coated in a methacrylic acid polymer, which makes the particles responsive to pH. These can be implanted deep into the tissues, where changes in pH levels then cause changes in the stiffness of the particles, which can be picked up by a standard ultrasound scanner outside the body. This was demonstrated in gel phantoms simulating biological tissue, in mouse cadaver tissue and in live mice.
According to the researchers, monitoring pH levels in tumors in this way could offer a non-invasive way of tracking how a tumor responds to drugs in real time, thereby allowing dosages to be adjusted to meet individual patient needs. But they hope the technology will come to offer far more than that, noting that the nanoparticles could be adapted to track more complex biomarkers, such as oxygen to monitor the impact of stroke, or proteins related to other diseases.
The scientists will now begin testing the technology on actual animal models of disease. Ultimately, they hope the technology will be able to work with something like a mobile phone, negating the need for complex hospital or lab equipment and opening up new possibilities when it comes to treating patients in remote areas.
The research was published in the journal ACS Sensors.
Source: Monash University via EurekAlert